It appears that you found the simple interest instead of using the given formula. You are given $\displaystyle{P}={12},{000}\usepackage{cmbright}\Huge\$ , $\displaystyle{r}={0.06}\usepackage{cmbright}\Huge\$ , $\displaystyle{m}={12}\usepackage{cmbright}\Huge\$ , and $\displaystyle{t}={5}\usepackage{cmbright}\Huge\$ . Substitute these values into the formula and simplify.